Some affluent countries are phobic about germs. In the United States, for instance, dispensers for hand sanitizers can be found in supermarkets, drugstores and even restaurants. While cleanliness is important, obliterating all foreign microbes is not so wise.
The hygiene hypothesis suggests that reduced exposure to infections in early childhood causes poor immune responses to allergens.
Microbes stimulate the immune system and certain variations in gut colonies are associated with the development of atopic disease. Clinical trials suggest that probiotics may prevent atopic eczema.
How do probiotics do this?
It is not certain but it is posed by researchers that improved epithelial barrier function and also changes in a developing immune system may be the mechanisms.
A June 2014 study from the United Kingdom tested strains of lactobacilli and bifidobacteria against placebo in mothers and infants in the perinatal period on atopy.
Eczema at 2 years in the offspring was similar in the probiotic and placebo groups. However, the frequency of skin prick sensitivity at 2 years was reduced in the probiotic compared with the placebo. The differences were mainly in sensitization to cow’s milk and hen’s egg proteins at 6 months. Atopic eczema occurred in 5.3% of children in the probiotic group but 12% in the placebo.
Preventing allergic disease has been difficult. Globally rates are soaring. Intervention with probiotics may be a viable tool.